Got one of these myself this Friday. As I won't be going home inbetween class and the party I'll be keeping it simple and dress up like Charlie Chaplin. Partly because it is the only excuse someone has these days to have a hitler stache. Bringing a blazer, bowler hat and a cane and I'll draw myself a nice hitler stache with some eye liner. Put some eye liner round the eyes and done.
Technically I would need a vest and oversized pants and shoes, but I doubt my audience is that familiar with Chaplin, so as long as I do a silly walk with a silly expression as I come in I should be fine. My experience with these kinda things is that you don't wanna overdo it because your costume only matters the first 10 minutes and after that its just a party. Just do enough to not be that guy wearing in the sweatpants and t-shirt.
You could go as a Mexican or something, just need a poncho, sombrero and an enormous (fake) mustache. 15 euros in any party shop should get you a long way. You need a sombrero in your daily life anyway, everyone does. Preferably you also need a ukelele and be able to play some mariachi, shit that is what I need to do for the next party. You could also buy a full costume, like a military one. Will cost you a little more and I tend to think they look shit and cheesy, but if you got money and are lazy. One shitty costume I find hilarious is one of dem Superman muscle shirts. Those are boss.
